Adjustable feed control for sewing machines



W. PEARSQ N ADJUSTABLE FEED CONTROL FOR SEWING MACHINES Filed April 9, 1921 2 Sheets-Sheet 1 Elgv4. mm; 1

u\\ w; I 66 7? v :5 R\ w I j z $41 g 7 7 40 1772219275197 66 M W W Feb. 10. 1925.

W. PEARSON ADJUSTABLE FEED CONTROL FOR SEWING MACHINES Filed April 9, 1921 2 Sheets-Sheet 2 I Patented Fe. it), 1925.

VITALTER PEARSON, GE "WHITMAN, MASSACHUSETTS.

ADJUSTABLE GUIQ'IRO'L F03 SEIVING- IJIACHINES.

Application filed April 9,

T 0 all. whom it may concern-.-

Be it known that I, WALTER Pniinson, a citizen of the United States, and resident of Whitman, in the county of Plymouth and State of Massachusetts, have invented an Improvement in Adjustable Feed Controls for Sewing Machines, of which the following description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

My present invention is an improved and novel construction permitting the adjustable spacing of the feeding devices in a sewing machine, particularly a shoe sewing machine such as the so-called McKay type of shoe sewing machines as disclosed in the patent to Blake, 201,987, dated April 2, 1878 and patent to Meyer, 1,298,759, dated April 1, 1919. In machines forming a chain stitch, such for example as the McKay sewing machines above mentioned, it is essential that the stitching and feed ing devices operate at a predetermined point, relatively with the sewing horn on which the article to be operated upon is mounted and where a whirl or cooperating chain stitch forming device is positioned. Thus for example, in the case of McKay stitchers the sewing horn-on which a shoe is fitted, must be in alinement with the reciprocating needle in the stitching devices of the head and the spacing of the stitching is efi'ected by the feeding devices. Therefore the length of feed controls the length of stitch and the number of stitches to be set, as well as the fineness, tension, tightness and speed.

Heretofore, in McKay stitching machines, or in all straight needle chain stitch mechanisms, so far as I am advised, it has been difficult to provide adjusting means for the spacing of the stitching and controlling the operation of the feeding elements. is these feeding devices were actuated by a cam or the like at the rear of the machine, a shifting of the cam effected a rough adjustment, but was entirely unsuitable for fine work and was ditlicult to change. Consequently, in McKay sewing machines, a variation in the spacing and consequently in the stitching, has always been limited in practice to from three to six stitches to the inch. This resulted in a very unsatisfactory, coarse and rigid McKay stitching in shoes, leaving the stitch- 1921. serial No. 459,987.

ing as a ridge on the insole of the shoe, as well as producing an uneven tension, lack of uniformity and rough stitch formation. by present invention, wherein I provide easily and readily adjustable controlling devices for the operation of the feediio' elements, and hence for the spacing C: of the stitching in McKay shoe work, enables a close and line stitch to be set, and therefore greater uniformity in the work, and resulting flexibility in the shoe thus sewed. A further advantage by havthe stitching in McKay work set closely is that the chain stitch portions are drawn entirely within the thickness of the soles being sewed together, preventing undesirable ridges in the shoe, as well as uniting the soles firmly. By means of my invention I am enabled to enlarge the range of the stitches in a McKay shoe from three to six of the stitches in a McKay shoe which was the prior range, to two to sixteen. stitches to the inch. Furthermore, I effect this desirable capacity by apparatus which can be instantly, readily, securely and accurately adjusted by unskilled labor and by any operator, and preferably in connection with a graduated scale, determining and illustrating exactly the stitches de sired and which will be produced by the controlling and adjusting apparatus when thus set to the indicated number. A still further feature and important advantage in my present invention is that I secure this adjustment in the feeding and conse quently in the stitches set, from a predetern'iined fixed point. Thus, throughout the entire range of the adjustment attained by the present invention, i. e., moving the feeding element, I have so constructed and arranged the adjustment and controlling members that the feeding element will always initiate or begin its feeding action at identically the same point relatively with the stitching needle and the feeding horn;

In carrying out my invention I have also so developed it that it can be applied to existing iilcliay stitching machines, without materially altering the construction, opera tion or timed relation of the moving instrumentalities. The importance of this feature will be appreciated when it is considered that, in these stitching machines, the actions of the feed, presser foot, and stitching devices are necessarily timed for exact and precise movement in synchronism.

Ill)

Thus the presser foot or work support must be locked in rigid position to resist the withdrawing action of the needle and then unlocked in timed relation with the moving action of the feeding element to release the work and permit the teed for the succeeding stitch. Any adjustments therefore on the stitch feeding connections and devices, must be made with a view of acting and cooperating with the presser foot, release mechanism, and locking members. This l accomplish by means or my present invention, while still permitting the wide range of adjustment and control for the feeding mechanisms.

To this end I prefer to apply my iniproved adjustments to the oscillating rock arm which effects the movement of the feeding element as well as the locking and unlocking of the presser toot,it having been usual heretofore to actuate the presser :ioot releasing and locking mecha nism by this rock arm which in turn would be oscillated by a suitable cam at the rear of the machine.

Further important details, advantages and novel combinations will be hereinafter described and claimed.

Referring to the drawings, illustrating a preferred embodiment of the invention,

F 1 is a front view oi a portion of the head on a McKay stitching machine wherein my invention is embodied;

Fig. 2 is a side view;

Fig. 3 is a side view of the oscillating rock arm equipped with my adjustment device; and

Fig. 4 is a plan view on the line t l Fig. 3.

ltelerring to the drawings, illustrate a portion only of t i standard and well known type 01: sewing machine, a part only of such machine being herein illustrated, the remaining parts being omit-ted for the sake oi clearness. In such machine fixed portions or plates in the head, 1 and 2, are shown throu T which the moving devices are adapted to slide or move. The needle bar 4t may be 0t usual and ordi nary construction witii means to reciprocate the same, and a sliding blocl-t 5 car the work rest or foot 6 a: mounted in a holde '1 is also ar: ngeo. to move vertically tin ll an appropriate slot in the lower plate '1. this pro foot being normally held downwardly by a coiled spring 8 bearing between collars 10 and 11, and adapted to be lifted by a handle 12 to insert or remove the work from the cooperating rotatable sewing horn of the machine.

Secured to the block 5 is a plate 15 having formed therein. a cam path 16 and adjacent this plate is the feed lever 20. This lever is adapted to slide through a grooved portion of the block 5, clearly shown in dotted lines,

l igs. l and 2 he eas es extending through the cam path l6 in a torward the plate thus providing for feeding action of when the latter is: on the permitting a tree upuard movement of the ever when the entire block 5 is lifted and imilarly permitting a retracting movement of the feeding ll Y 1611 the linlr 30 --ted by a strap 33 pivoted at to the A time of the lever 20 and connected with a contractile spring 35, having one end secured to the strap 33 and its other end attached to a catch 36 rigidly secured to a portion of the lined frame oi the machine. This construction also insures that the feed ing element will always be drawn backwardly to a predetermined point, i. e., preferably in contact with the work rest or pressor foot 6, which latter is at all times in alinenient with and relatively spaced from the needle rod d, and the sewing horn cooperating therewith.

To effect an adjustable feeding actuation of the link 30 and consequently oi? the feed loot 25, l utilize the usual rock shaft ll) pivotally mounted on a shaft 39 held in suitable bearings and 4-2, tornied on the carrying arms and it: upper portion a :l by a cam l il to the arm and consequently 1" is rock shatt 4.4: at Pil'Qi'l'GljGi'li '"ied times in the cycle oi? operation or: the machine, at present usual in machines or? this type. The arm also carries an upwardly extending pordowiwardly during the raising of the needle bar 4: and r ease the same during the feeding action or the element also as a l known constriu-tion. Pivotally secured to the arm ll at (30 is ud in exact alineinent with that oi the roll it? which is actuated by the cam 50. said having morn ed thereon one end of the rug lever 61, me other end oi said lever pivotally coni'iected to the link 30 at 63, 1. This lever 61 with its uppermost -ated by the oscillation of the rock l0 through actuation of the cam 50, roll 48 and arm 43, as above described, will effect the forwardly feedin action oi the nseepss element- 25 by the rocking of said arm 61 upon a fulcrum. I provide an adjustable fulcrum to control, predetermine and adjust the throw or feeding action of this lever 61 on the link 30. To this end 1 form a considerable length of the lever 61 in the form of an arcuate slot, as illustrated at 66, having its inner surfaces in concentric lines and adapted to contain a sliding fulcrum block 70. This block 70 is bored to receive a pivot '71 which pivot extends into the bosses or bearings 72 at each side of the arm 66 and is a portion of a movable member 75, the latter being pivoted at 7 6 to a bracket 77 mounted on the plate 1.

In order to hold this arm 75 in desired adjusted position with the sliding fulcrum block 70, in any desired position to control the throw and feeding movement of the lever 61, I also provide a slotted portion 78 formed on lines concentric with that of the walls of the portion 66, through which slot 78 is fit-- ted a shank of an adjusting screw 80. Consequently as the adjusting screw 80 is loosened and the member 7 5 is raised or lowered to shift the fulcrum block 70 and thereupon the adjusting screw 80 tightened, the member 75 will thus be held in its adjusted position with the fulcrum block 70 in desired relationship for the control and adjustment of the feeding action of the lever 61.

In order to facilitate the adjusting move-- ment of the same I prefer to form on one or ge of the portion 66, a series of indications or grade marks, as noted at 82, which correspond with an indicator 83 on the outer surface of the part 72 carrying the bearing for the fulcrum block, these indications being arranged proportionately so as to illustrate, indicate and control the number of stitches to the inch which the machine as thus set will produce, said indications being graduated for the corresponding feeding movements of the feeding element 25, as controlled y the setting of the fulcrum block 70, as will be readily understood.

The operation of the adjustment and control will be readily appreciated. The rock shaft 40 being of usual and ordinary con struction is fitted with the extra lever 61, and the associated parts as above described, consisting in the movable fulcrum block therefor and the means to adjust said block and hold it to its adjusted position. None of the otner actuating, working and moving parts of the machine need be specially My lnventlon is there formed. or altered.

fore readily applicable to existing sewing machines of this type, by applying the ad justable features for the control of the length of feed as above explained. Furthermore the feeding action is in timed unison with the locking and release mechanism of the presser foot 6 and with the reciprocating movements of the needle bar 4, as well as cooperating in timed relation with the stitching devices within the rotatable horn of this type of chain stitch machine.

The operator can readily adjust the machine for the length of stitch desired and when so adjusted the superintendent or foreman can see that same is correct during the continuous operation of the mechanism.

A further advantage consists in the fact that by having this adjustment within view in the front of the machine, I are enabled to secure the several cams and particularly the cam onto its shaft rigidly and in fixed predetermined position without any subsequent necessity for shifting or altering the same. This is a decided improvement in actual practise, since the slightest shifting of the cam 50 interferes with the entire timed relation of the machine. This has been one of the difliculties heretofore experienced in the efforts of the operators to change the adjustment of the machine, all of which difliculties are eliminated by my present invention.

My present invention is further described and defined in the following claim.

A sewing machine having stitch forming mechanism, a movable work feeding element, a cam, a rock shaft, an arm formed integral therewith, a cam roller mounted on said arm, said cam roller being movable into the path of movement of the cam, second arm equal in length to the length of the first said arm, a lever moved by said second arm, a linkage connecting the end of said lever to the work feeding element, said lever being provided with an arcuate slot, a movable fulcrum for said lever adjustably mounted in said slot, an arm pivotally mounted on and adjustably connected to a rigid portion of the machine, a gauge to indicate the extent of movement of said fulcrum proportionate to the number of stitches controlled by the feeding element, and means to hold the arm and fulcrum in adjusted position.

In testimony whereof, I have signed my name to this specification.

WALTER PEARSON. 

